linux/arch/arm/include/asm/hw_breakpoint.h
Will Deacon 864232fa1a ARM: 6357/1: hw-breakpoint: add new ptrace requests for hw-breakpoint interaction
For debuggers to take advantage of the hw-breakpoint framework in the kernel,
it is necessary to expose the API calls via a ptrace interface.

This patch exposes the hardware breakpoints framework as a collection of
virtual registers, accesible using PTRACE_SETHBPREGS and PTRACE_GETHBPREGS
requests. The breakpoints are stored in the debug_info struct of the running
thread.

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: S. Karthikeyan <informkarthik@gmail.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-09-08 10:05:00 +01:00

134 lines
3.3 KiB
C

#ifndef _ARM_HW_BREAKPOINT_H
#define _ARM_HW_BREAKPOINT_H
#ifdef __KERNEL__
struct task_struct;
#ifdef CONFIG_HAVE_HW_BREAKPOINT
struct arch_hw_breakpoint_ctrl {
u32 __reserved : 9,
mismatch : 1,
: 9,
len : 8,
type : 2,
privilege : 2,
enabled : 1;
};
struct arch_hw_breakpoint {
u32 address;
u32 trigger;
struct perf_event *suspended_wp;
struct arch_hw_breakpoint_ctrl ctrl;
};
static inline u32 encode_ctrl_reg(struct arch_hw_breakpoint_ctrl ctrl)
{
return (ctrl.mismatch << 22) | (ctrl.len << 5) | (ctrl.type << 3) |
(ctrl.privilege << 1) | ctrl.enabled;
}
static inline void decode_ctrl_reg(u32 reg,
struct arch_hw_breakpoint_ctrl *ctrl)
{
ctrl->enabled = reg & 0x1;
reg >>= 1;
ctrl->privilege = reg & 0x3;
reg >>= 2;
ctrl->type = reg & 0x3;
reg >>= 2;
ctrl->len = reg & 0xff;
reg >>= 17;
ctrl->mismatch = reg & 0x1;
}
/* Debug architecture numbers. */
#define ARM_DEBUG_ARCH_RESERVED 0 /* In case of ptrace ABI updates. */
#define ARM_DEBUG_ARCH_V6 1
#define ARM_DEBUG_ARCH_V6_1 2
#define ARM_DEBUG_ARCH_V7_ECP14 3
#define ARM_DEBUG_ARCH_V7_MM 4
/* Breakpoint */
#define ARM_BREAKPOINT_EXECUTE 0
/* Watchpoints */
#define ARM_BREAKPOINT_LOAD 1
#define ARM_BREAKPOINT_STORE 2
/* Privilege Levels */
#define ARM_BREAKPOINT_PRIV 1
#define ARM_BREAKPOINT_USER 2
/* Lengths */
#define ARM_BREAKPOINT_LEN_1 0x1
#define ARM_BREAKPOINT_LEN_2 0x3
#define ARM_BREAKPOINT_LEN_4 0xf
#define ARM_BREAKPOINT_LEN_8 0xff
/* Limits */
#define ARM_MAX_BRP 16
#define ARM_MAX_WRP 16
#define ARM_MAX_HBP_SLOTS (ARM_MAX_BRP + ARM_MAX_WRP)
/* DSCR method of entry bits. */
#define ARM_DSCR_MOE(x) ((x >> 2) & 0xf)
#define ARM_ENTRY_BREAKPOINT 0x1
#define ARM_ENTRY_ASYNC_WATCHPOINT 0x2
#define ARM_ENTRY_SYNC_WATCHPOINT 0xa
/* DSCR monitor/halting bits. */
#define ARM_DSCR_HDBGEN (1 << 14)
#define ARM_DSCR_MDBGEN (1 << 15)
/* opcode2 numbers for the co-processor instructions. */
#define ARM_OP2_BVR 4
#define ARM_OP2_BCR 5
#define ARM_OP2_WVR 6
#define ARM_OP2_WCR 7
/* Base register numbers for the debug registers. */
#define ARM_BASE_BVR 64
#define ARM_BASE_BCR 80
#define ARM_BASE_WVR 96
#define ARM_BASE_WCR 112
/* Accessor macros for the debug registers. */
#define ARM_DBG_READ(M, OP2, VAL) do {\
asm volatile("mrc p14, 0, %0, c0," #M ", " #OP2 : "=r" (VAL));\
} while (0)
#define ARM_DBG_WRITE(M, OP2, VAL) do {\
asm volatile("mcr p14, 0, %0, c0," #M ", " #OP2 : : "r" (VAL));\
} while (0)
struct notifier_block;
struct perf_event;
struct pmu;
extern struct pmu perf_ops_bp;
extern int arch_bp_generic_fields(struct arch_hw_breakpoint_ctrl ctrl,
int *gen_len, int *gen_type);
extern int arch_check_bp_in_kernelspace(struct perf_event *bp);
extern int arch_validate_hwbkpt_settings(struct perf_event *bp);
extern int hw_breakpoint_exceptions_notify(struct notifier_block *unused,
unsigned long val, void *data);
extern u8 arch_get_debug_arch(void);
extern u8 arch_get_max_wp_len(void);
extern void clear_ptrace_hw_breakpoint(struct task_struct *tsk);
int arch_install_hw_breakpoint(struct perf_event *bp);
void arch_uninstall_hw_breakpoint(struct perf_event *bp);
void hw_breakpoint_pmu_read(struct perf_event *bp);
int hw_breakpoint_slots(int type);
#else
static inline void clear_ptrace_hw_breakpoint(struct task_struct *tsk) {}
#endif /* CONFIG_HAVE_HW_BREAKPOINT */
#endif /* __KERNEL__ */
#endif /* _ARM_HW_BREAKPOINT_H */